Post by Jeff Martin on Jan 22, 2012 15:20:31 GMT -5
If it isn't obvious to everyone by now, Brian Manzella, golf's self-proclaimed "Answer Man", doesn't particularly like answering questions, but even worse, he's positively dreadful at explaining important concepts, and creates more questions by his "pronouncements" than he answers.
For two days, chaos was reigning in this thread simply titled "Efficiency...":
www.brianmanzella.com/golfing-discussions/16714-efficiency.html
Manzella starts the thread with this "ball of confusion":
Then offers this "elaboration", which is simply wrong, only fueling further confusion:
Get it? Hell if I do: it is hard to imagine these concepts being presented in a more uninformative way. And I'm not at all convinced Dr. Nesbit is right in his conclusion that "all swings are pretty much the same as far as efficiency" is concerned. More on that later.
Let's start with a definition of "work" in physics (from Wikipedia):
So, "work" is the amount of energy transferred to an object during movement: lifting a box off the floor and putting it on a the kitchen table is "work". Lifting the same box off the floor to over your head is more work. Holding the box still against your chest (once it's been lifted) will require a supporting force, but, unless the box is moved, there will be no "work", and no energy transferred to the box simply by holding it.
For some reason, Manzella thinks "effort" is something different than "work". He should try consulting a dictionary; the first one I looked at on-line had this definition of "effort" which appears to be the relevant one for this discussion:
So, the "effort required to lift the box over my head" is equal to all the work expended lifting the box over my head. And the "work" is the energy transferred to the box by applying the lifting force across the distance from the floor to over my head.
So, let's turn to the Nesbit paper (co-authored with Monika Serrano in 2005) Work and Power Analysis of the Golf Swing, which is a favorite source of Manzella misinformation.
www.jssm.org/vol4/n4/18/v4n4-18pdf.pdf
In it Dr. Nesbit estimates the total amount of work, or effort, expended by moving the body in the golf swing. Of course, this means adding up the total energy transferred by the body's muscles to various body parts by moving them. He studied just four amateur subjects: three men, one at scratch, a 5 handicapper and an 13 handicapper, and one woman, an 18.
In the table below, the "Total Body Work" is highlighted:
Not surprisingly, the best male player, the scratch, expended the most effort, or work, during the swing, 1,452 newton-meters, meaning he transferred the most energy from the muscles to the torso and limbs by moving them. Also, not surprisingly, the 18 handicap woman performs the least amount of work and transferred the least energy to the torso and limbs.
The same exercise is performed for the clubhead: an estimate is calculated of the energy transferred to the clubhead, or total work done, by applying forces to move the clubhead. That estimate is highlighted in the line "Total Work".
Again, not surprisingly, the scratch player transfers the most energy to the clubhead by doing the most work: 355 newton-meters. The two male handicap players expend similar amounts of work, and, of course, the 18 handicap female, the least.
The "efficiency" Manzella is referring to is the bottom line on table 3 above, also highlighted: "Swing Efficiency". That is calculated by dividing the clubhead "Total Work" from table 3 by the "Total Body Work" in table 2. The higher the percentage, the more "efficient" the swing. Interestingly, the female 18 handicapper has the highest "efficiency" at 26.8%! Presumably, because the "Swing Efficiency" range was from a low of 20.2% (the male 5 capper) to the high of 26.8%, Nesbit feels comfortable stating at AS2 that "swing efficiency" doesn't vary much depending on skill. However, this conclusion appears to be based on a shockingly small sample size that does not contain any professionals or tour players, let alone any elite tour players.
More importantly, despite what Nesbit said, the study shows there can be as much as a 35% difference in efficiency between the examined swings, so I don't know how one can responsibly claim that "swing efficiency" is "pretty much the same" among "all swings". On a common sense level this is silly, and Nesbit's data doesn't even support it.
So what can be said about all this? A lot of energy is expended moving the body around during a golf swing and, based on one very limited study, only about 20 to 27% of that energy is transferred to the clubhead. And, not surprisingly, the best players transfer the most energy through "work": applying various forces over various distances, from the muscles to the torso and limbs and to the clubhead.
So, what point was Manzella trying to make? I guess this post explains it: Manzella doesn't want forum members thinking that distance comes from mechanical efficiency, just from more "work": higher forces over longer distances:
But, of course, a conclusion like that would never fly here: he has absolutely no evidence beyond Nesbit's opinion, which appears to be based a one mightily narrow study which, in fact, contradicts him!
We know from simple physics that reducing the arms/club moment of inertia by pulling them in through "lag" (like Couples, Sadlowski and Lucas) will result in faster acceleration for the arms/club, assuming the same amount of rotational force, or torque, then having them extended (like Westwood, Cal Peete and Stricker). We also know from Kelvin's analyses (recently discussed in Anina's January 21st video lesson) that sequencing of "work" is critical for it to be useful: firing the right leg too soon will result in very little or perhaps none of that work getting transferred to the clubhead.
Manzella just seems to be flailing. His teaching is now all about "intent" and Trackman numbers. With posts like this, he seems to be trying to reinforce the old-fashioned notion that "speed" is "God-given", not a function of the right mechanics. Since he doesn't ever demonstrate that he KNOWS the right mechanics, I guess that is what he is reduced to promoting.
Jeff
For two days, chaos was reigning in this thread simply titled "Efficiency...":
www.brianmanzella.com/golfing-discussions/16714-efficiency.html
Manzella starts the thread with this "ball of confusion":
Then offers this "elaboration", which is simply wrong, only fueling further confusion:
Get it? Hell if I do: it is hard to imagine these concepts being presented in a more uninformative way. And I'm not at all convinced Dr. Nesbit is right in his conclusion that "all swings are pretty much the same as far as efficiency" is concerned. More on that later.
Let's start with a definition of "work" in physics (from Wikipedia):
So, "work" is the amount of energy transferred to an object during movement: lifting a box off the floor and putting it on a the kitchen table is "work". Lifting the same box off the floor to over your head is more work. Holding the box still against your chest (once it's been lifted) will require a supporting force, but, unless the box is moved, there will be no "work", and no energy transferred to the box simply by holding it.
For some reason, Manzella thinks "effort" is something different than "work". He should try consulting a dictionary; the first one I looked at on-line had this definition of "effort" which appears to be the relevant one for this discussion:
So, the "effort required to lift the box over my head" is equal to all the work expended lifting the box over my head. And the "work" is the energy transferred to the box by applying the lifting force across the distance from the floor to over my head.
So, let's turn to the Nesbit paper (co-authored with Monika Serrano in 2005) Work and Power Analysis of the Golf Swing, which is a favorite source of Manzella misinformation.
www.jssm.org/vol4/n4/18/v4n4-18pdf.pdf
In it Dr. Nesbit estimates the total amount of work, or effort, expended by moving the body in the golf swing. Of course, this means adding up the total energy transferred by the body's muscles to various body parts by moving them. He studied just four amateur subjects: three men, one at scratch, a 5 handicapper and an 13 handicapper, and one woman, an 18.
In the table below, the "Total Body Work" is highlighted:
Not surprisingly, the best male player, the scratch, expended the most effort, or work, during the swing, 1,452 newton-meters, meaning he transferred the most energy from the muscles to the torso and limbs by moving them. Also, not surprisingly, the 18 handicap woman performs the least amount of work and transferred the least energy to the torso and limbs.
The same exercise is performed for the clubhead: an estimate is calculated of the energy transferred to the clubhead, or total work done, by applying forces to move the clubhead. That estimate is highlighted in the line "Total Work".
Again, not surprisingly, the scratch player transfers the most energy to the clubhead by doing the most work: 355 newton-meters. The two male handicap players expend similar amounts of work, and, of course, the 18 handicap female, the least.
The "efficiency" Manzella is referring to is the bottom line on table 3 above, also highlighted: "Swing Efficiency". That is calculated by dividing the clubhead "Total Work" from table 3 by the "Total Body Work" in table 2. The higher the percentage, the more "efficient" the swing. Interestingly, the female 18 handicapper has the highest "efficiency" at 26.8%! Presumably, because the "Swing Efficiency" range was from a low of 20.2% (the male 5 capper) to the high of 26.8%, Nesbit feels comfortable stating at AS2 that "swing efficiency" doesn't vary much depending on skill. However, this conclusion appears to be based on a shockingly small sample size that does not contain any professionals or tour players, let alone any elite tour players.
More importantly, despite what Nesbit said, the study shows there can be as much as a 35% difference in efficiency between the examined swings, so I don't know how one can responsibly claim that "swing efficiency" is "pretty much the same" among "all swings". On a common sense level this is silly, and Nesbit's data doesn't even support it.
So what can be said about all this? A lot of energy is expended moving the body around during a golf swing and, based on one very limited study, only about 20 to 27% of that energy is transferred to the clubhead. And, not surprisingly, the best players transfer the most energy through "work": applying various forces over various distances, from the muscles to the torso and limbs and to the clubhead.
So, what point was Manzella trying to make? I guess this post explains it: Manzella doesn't want forum members thinking that distance comes from mechanical efficiency, just from more "work": higher forces over longer distances:
But, of course, a conclusion like that would never fly here: he has absolutely no evidence beyond Nesbit's opinion, which appears to be based a one mightily narrow study which, in fact, contradicts him!
We know from simple physics that reducing the arms/club moment of inertia by pulling them in through "lag" (like Couples, Sadlowski and Lucas) will result in faster acceleration for the arms/club, assuming the same amount of rotational force, or torque, then having them extended (like Westwood, Cal Peete and Stricker). We also know from Kelvin's analyses (recently discussed in Anina's January 21st video lesson) that sequencing of "work" is critical for it to be useful: firing the right leg too soon will result in very little or perhaps none of that work getting transferred to the clubhead.
Manzella just seems to be flailing. His teaching is now all about "intent" and Trackman numbers. With posts like this, he seems to be trying to reinforce the old-fashioned notion that "speed" is "God-given", not a function of the right mechanics. Since he doesn't ever demonstrate that he KNOWS the right mechanics, I guess that is what he is reduced to promoting.
Jeff
I can't understand wtf Manzella is talking about, it would seem that if you had 2 golfers doing the same amount of "work" with the same exact equipment and test conditions but one hit it farther than the other one isn't that swing more efficient? 
